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Crane, J.H. 1993. Commercialization of carambola, atemoya, and other tropical fruits in south Florida. p. 448-460. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.

Commercialization of Carambola, Atemoya, and Other Tropical Fruits in South Florida

Jonathan H. Crane


  1. CARAMBOLA
    1. Botany
    2. Horticulture
  2. ATEMOYA
    1. Botany
    2. Horticulture
  3. MISCELLANEOUS COMMERCIAL TROPICAL FRUITS
  4. TROPICAL FRUIT INDUSTRY DEVELOPMENT
    1. Limitations
    2. Facilitation
  5. REFERENCES
  6. Table 1
  7. Table 2
  8. Table 3
  9. Table 4
  10. Table 5
  11. Table 6
  12. Table 7
  13. Fig. 1
  14. Fig. 2

Introduction and commercialization of tropical fruit crops into south Florida has been occurring for over 100 years. Two of these crops, carambola and atemoya have begun to be grown commercially in the past 10 to 20 years. This paper will discuss the introduction and culture of tropical fruit crop production in southern Florida with emphasis on carambola and atemoya. Factors which enhance and inhibit commercialization of new tropical fruit crops will also be highlighted.

CARAMBOLA

Carambola or star fruit (Averrhoa carambola L., Oxalidaceae) was introduced into Florida over 100 years ago (Knight 1969; Knight 1987; Wolfe 1937) from Southeast Asia (Martin et al. 1987). However, until the early 1970s (Table 1), carambola had been grown only as specimen trees in botanical gardens and experiment stations and as a curiosity in home landscapes.

Carambola was thought to have commercial potential as early as 1941 (Anon. 1941). During the 1960s, there was a resurgence of interest in this fruit which was sold to local restaurants and specialty shops (Vines and Grierson 1966; Knight 1969). Interest was based mostly on its attractive star shape when cut in cross-section and yellow to golden color. Fruit from early introductions were however, sour and sometimes considered unpalatable. This limited market and public acceptance, inhibiting development and expansion of carambola as a commercial fresh fruit.

During the past 56 years introduction, evaluation, and selection of carambola fruit has been actively pursued in South Florida (Table 2) (Campbell 1970; Knight 1982; Wagner et al. 1975). Seeds and/or budwood have been introduced from Hawaii, Malaysia, Taiwan, and Thailand and numerous seedlings have been evaluated by the USDA Subtropical Horticultural Research Station and Germplasm Repository in Miami, Florida. Organizations such as the Rare Fruit Council International, nursery tradesman, and fruit growers have also planted, evaluated, and selected many new cultivars.

During the mid to late 1970s, Morris Arkin, a local nurseryman in Miami, selected a sweet carambola with good handling characteristics from a seedling population which was subsequently named 'Arkin'. Soon afterward, the limited commercial area of carambola under cultivation in south Florida (4 to 12 ha) was top-worked to 'Arkin' and this new cultivar lead to a rapid increase in consumer demand for the fruit which further stimulated interest in establishing new commercial plantings (Table 1).

Today, there is about 243 ha of commercial carambola in south Florida (Table 1). Production for the 1989-90 season was estimated at 1.1 million kg (packed) and production for the 1990-91 season is estimated at 1.6 million kg. The value of the crop is now estimated to be between $1.5 to $2 million annually (Tropical Fruit Advisory Council 1990).

Botany

The carambola is a small tree (7 to 10 m high). Mature seedling trees having a symmetrical canopy (Campbell and Malo 1981); grafted trees a range of shapes (e.g., upright or spreading) and growth habits. Leaves are compound with five to eleven leaflets (Ruehle 1967). Flowers are borne in panicles on twigs and small diameter branches in the leaf axils of present or fallen leaves (Ochse et al. 1961), along larger diameter branches including scaffolding limbs, and occasionally on the main trunk. Flowers are small (1 cm diam.) and perfect with five sepals and petals and pink to lavender in color (Campbell and Malo 1981). The fruit (Fig. 1) is a four to five celled fleshy berry, 5.0 to 12.5 cm long and 3 to 6 cm in diameter with five (sometimes 4 to 6 or more) longitudinal ribs (Ochse et al. 1961). Fruit weight ranges from 100 to 110 g or more (Campbell and Koch 1989) and the waxy exocarp is thin, smooth, and light yellow to dark orange-yellow (Campbell and Malo 1981; Ochse et al. 1961). Fruit flesh is yellow, crisp, and juicy with a mild to strong sour or sweet taste.

Horticulture

Adaptation. Carambola trees are best adapted to hot, humid, wet tropical or subtropical lowland areas (Campbell and Malo 1981; Martin et al. 1987). Air temperatures at or below -1.7° to -2.8°C may kill young trees and damage leaves and twigs on mature trees (Campbell et al. 1985). Mature trees may be severely damaged or killed at temperatures of -4.4° to -6.7°C (Campbell et al. 1985). Overhead, high volume sprinkler irrigation has been observed to be effective in protecting trees and fruit from prolonged freezing temperature.

Carambola cultivars grown and tested in Florida vary in wind tolerance. For instance, 'Golden Star' appears more tolerant to planting in areas exposed to high winds (e.g., >40 km/h) and constant buffeting, whereas newly planted 'Arkin' trees may be stunted and unhealthy in the same location. Constant and strong winds during early to mid-spring can cause desiccation, defoliation, twig and stem dieback, and fruit scarring. Observations indicate planting carambola trees adjacent to natural wind-breaks such as pinelands, hammocks, and Australian pines, within manmade wind-breaks, or interplanting with other crops (e.g., papaya, avocado) enhances the growth, development, and production.

Carambola trees are tolerant of a variety of soil types as long as they are well drained (Campbell and Malo 1981). Joyner and Schaffer (1990) report that carambola trees are moderately flood tolerant. Young 'Golden Star' trees survived continuous or intermittent flooding over an 18 week period. However, flooding decreased carbon assimilation, transpiration, and biomass accumulation compared to non-flooded controls.

Carambolas grow best in neutral to mildly acid pH soils (Campbell et al. 1985) while trees growing in the calcareous high pH soils (pH 7.5 to 8.5) of south Florida often show symptoms of iron, manganese, and magnesium deficiency. These deficiencies may be prevented by periodic foliar applications of micronutrients and soil drenching with iron chelated materials.

Propagation, rootstocks, and cultivars. Trees can be propagated by seed, grafting, budding, and air layering (Campbell et al. 1985). Recently, gibberellic acid applied in a lanolin paste to the basal stem of young seedlings increased stem diameter growth rate, thus reducing the time for plants to reach graftable stem diameter from an average of 93 days to 47 days (Marler and Mickelbart 1991). Currently, a plant is ready for field planting 16 to 24 months after grafting. Propagation by tissue culture has been only partly successful, as shoots but not roots have been regenerated (Litz and Griffis 1989).

Generally, seedlings derived from open pollinated 'Golden Star' and 'Dah Pon' (M-18690) are used as rootstocks in south Florida. This is based on limited rootstock development and selection which compared seedling survival and deficiency symptoms of several crosses over a two-year period (Knight 1982).

Many cultivars have been introduced and evaluated in south Florida during the past 50 odd years (Table 2). Of these, two cultivars stand out: 'Arkin' the primary sweet cultivar grown in south Florida, comprising at least 98% of the current hectarage (Crane 1989); and 'Golden Star' the primary tart cultivar (Campbell 1965). Many of the cultivars introduced into south Florida have proved unsatisfactory for one reason or another. For example, although 'Fwang Tung' is a sweet cultivar, but its large, thin ribs are easily damaged during handling and 'Demak', also sweet, has a bitter after-taste.

Plant spacing, fertilization, and irrigation. There is a broad range of plant spacings and densities (173 to 701 trees/ha) used in carambola production (Crane 1989). However, most (about 60%) of the groves currently employ a 4.6 to 6.1 m spacing within rows and 6.1 to 7.6 m spacing between rows resulting in between 286 to 356 trees/ha. Optimum plant spacing and densities have not been investigated.

Little work has been done concerning fertilizer and irrigation practices for carambola. Current recommendations are based on observation. General fertilizer recommendations include 4 to 6 or more applications of a 6-2.6-5.0 or 11-1.7-10 (NPK) or similar material applied at a rate of 560 kg/ha per application, 1 to 3 foliar applications of micronutrients (manganese, zinc), and 2 to 3 soil drench applications of chelated iron (Campbell et al. 1985; Campbell and Malo 1981). Ferguson et al. (1988) found no difference in trunk calipers and tree heights between young carambola trees fertilized with slow release and standard materials suggesting application frequency could be reduced without reducing tree growth.

The water requirements of carambola have not been determined. Currently 2.54 to 5.1 cm of water are applied after 7 to 10 days of little or no rainfall.

Pruning and tree size control. Little research has been conducted in south Florida on carambola pruning. Generally, young trees are not trained and because the industry is only about 10 years old, tree size control is only now becoming critical in commercial groves. Preliminary results from current field trials on selectively pruned six year old carambola trees has shown the lower and mid-tree canopy remain productive despite pruning of the upper canopy. Furthermore, because only fruit from the ground to about 3.7 m is easily picked, annual pruning at a 3.7 to 4.3 m height may be feasible and result in commercially acceptable yields.

Diseases and insect pests. Several insects may cause damage to carambola fruit including stink bugs, Acanthocephala sp., fruit blotch miner (Pena 1986), red-banded thrips [Selenothrips rubrocinctus (Giard)], and soft brown scales [Coccus hesperidum (L.)] (J.E. Pena pers. commun.). Other pests such as Plumose scale [Morganella longispina (Morgan)] and Philephedra scale [Philephedra tuberculosa (Nakahara & Gill)] attack twigs and small stems causing defoliation and stem die-back (Pena 1986). Reniform nematodes [Rotylenchulus reniformis (Linford & Oliveira)] have been associated with tree decline (Campbell et al. 1985). Birds may attack fruit especially early in the harvest season.

Several leaf spot diseases caused by Cercopsora averrhoae Petch., Corynespora cassiicola Berk. & Curt. (McMillan 1986), Phomopsis sp. and Phyllosticta sp. (Campbell et al. 1985), may cause premature leaf drop. Ripe and injured carambola fruit may be attacked by anthracnose (Colletrotrichum gloeosporioides Penz.) (McMillan 1986) while a Leptothyrium sp. has been identified with "sooty-mold" symptoms on fruit (Simone and Kuchareck 1988). Pythium splendens Braun has been recently identified as the cause of a general tree decline syndrome which includes defoliation, twig and root die-back, and reduced fruit production (Ploetz 1991).

Harvest, handling, and utilization. Carambola trees are precocious and generally begin fruit production within the first 12 to 18 months of planting. Five year old trees may produce 45 kg per tree per year while more mature trees (8 to 13 years old) may produce between 90 to 181 kg per tree per year (Campbell et al. 1985). In Florida, some carambolas are available all year, but the commercial season generally ranges from July to February/March. Fruit development takes about 61 to 70 days depending upon cultivar and weather conditions (Campbell and Koch 1989).

Proper harvesting is critical to successful storage and marketing of the fruit. Fruit are carefully harvested by hand at "color break," placed in field boxes, and transported to packinghouses for grading, packing, and storing. Carambolas are non-climacteric (Osland and Davenport 1983) but will develop normal color if picked at color break (Campbell et al. 1987). Fruit can be stored for up to 44 days at 5°C and 85 to 95% relative humidity without suffering chilling damage and develop normal color when transferred to 23°C (Campbell et al. 1987).

Carambola is primarily sold as a fresh fruit although small quantities are sold pickled, in sauces, and jellies. Fresh fruit is incorporated into a wide variety of dishes, salads, desserts, and drinks. Carambola can also be cut in cross-section and dried (Campbell and Campbell 1983).

ATEMOYA

Atemoya trees are hybrids of Annona squamosa L. (sugar apple) x A. cherimola Mill. (cherimoya) which either result from natural crosses (Morton 1987) or result from a breeding program (Fairchild 1974; Fairchild 1990; Morton 1987). The first recorded manmade crosses occurred in Miami in 1908 (Fairchild 1990; Morton 1987). Natural hybrids have been found in Venezuela (Popenoe 1974) and chance hybrids were noted in adjacent sugar apple and cherimoya groves in Israel during the 1930s and 1940s (Morton 1987). The name atemoya was proposed by P.J. Wester for these sugar apple, cherimoya hybrids and combines "ate," an original name for sugar apple, with "moya" taken from the last two syllables of cherimoya (Fairchild 1990).

The purpose of the initial crosses among sugar apples and cherimoyas was to incorporate the excellent fruit quality and cold tolerance of the subtropically adapted cherimoyas (which did not grow or fruit well in humid lowland areas like south Florida) with the sugar apple which is well adapted to warm, humid, subtropical, and tropical climates (Fairchild 1990). Some seedlings of these early crosses appeared to produce fruit with excellent quality (Fairchild 1990) and possessed sufficient cold hardiness to have survived freezing weather (-3.1°C) in 1917 (Morton 1987).

Despite these early breeding successes and introduction of numerous cultivars (Table 3) from countries such as Israel and Venezuela (Popenoe 1974), atemoyas remained a home garden and specimen tree in botanical gardens and germplasm repositories until the early (Campbell 1983) to mid-1980s (Anon. 1986) (Table 4). This was due to poor fruit set and yields, alternate bearing, splitting of mature fruit, and uneven ripening of these early selections (Popenoe 1974).

Commercial development of the crop was greatly facilitated by the introduction 'Gefner' atemoya from Israel which is a fairly reliable bearer of good quality fruits. Even so, the search and development for superior atemoya cultivars continues in south Florida, both by private individuals (Mahdeem 1989; Mahdeem 1990) and at the USDA Subtropical Research Unit and Germplasm Repository in Miami.

Today, south Florida has about 49 ha of commercial atemoyas (Table 4). Production is estimated to be about 68 to 91 kg annually and the crop worth $250,000 to $400,000.

Botany

The atemoya is a member of the Annonaceae and is a small tree (up to 10 m) with a symmetrical, globose, dense canopy. Leaves are lanceolate, ovate, or elliptic, and deciduous (Campbell and Phillips 1980). Flowers possess 3 fleshy petals, are yellowish-green, and are borne singly or in clusters of 2 to 3 in leaf axils on new shoots or 1 to 2 year old wood (Campbell and Phillips 1980). Fruit type is aggregate, formed by the coherence of many pistils (Fig. 2). Fruit is green to greenish-yellow, conical to ovate shaped, with slight to pronounced surface protuberances (Campbell and Malo 1980). Pulp is white, smooth textured, containing 10 to 40 dark brown to black seeds per fruit. Fruit weigh between 225 to 450 g (Campbell and Malo 1980).

Horticulture

Adaptation. Atemoyas are adapted to a wide range of temperatures, from lowland tropical to cool subtropical climates. In south Florida during January 1977, young trees were killed or severely injured by prolonged temperatures between -6.7° to -3.9°C whereas mature trees withstood those temperatures with slight to moderate damage (Campbell et al. 1977). High volume overhead and under tree irrigation were observed to protect young and mature trees during the 1989 freeze in South Florida.

Observation by the author suggests strong, constant winds during late winter and spring may cause young atemoya trees to either lean in the leeward direction and/or to develop canopy and limbs only on the leeward side giving trees an unbalanced canopy.

Atemoyas are adapted to a range of soil types as long as the soils are well drained (Campbell and Phillips 1980; Morton 1987). Micronutrient deficiencies appear to be less of a problem in soils with a neutral to moderately acid pH (5 to 7). In the high pH calcareous soils of South Florida, micronutrient deficiencies can be prevented with the use of micronutrient foliar sprays of manganese and zinc and chelated iron soil drenches.

Propagation, rootstocks, and cultivars. Atemoyas may be propagated by seed, grafting, and budding. However, fruit quality and production of seedlings is extremely variable. Trees may be veneer, cleft or whip grafted (Campbell and Phillips 1980; Morton 1987) and pre-graft preparation of budwood increases success (Ogden et al. 1981). Grafted trees begin to produce fruit in 3 to 4 years.

Several rootstocks have been recommended for atemoya, including pond apple (Annona glabra L.), custard apple (A. reticulata L.), sugar apple (A. squamosa L.), and atemoya (Campbell and Phillips 1980). However, delayed incompatibility problems occur with pond apple (Campbell and Phillips 1980) and custard apple (Cockshutt 1990). At present, sugar apple and atemoya seedlings are the most commonly used rootstocks. Seeds of atemoya and sugar apple appear to have an after ripening requirement of 3 to 6 months which delays planting for seedling rootstocks.

A number of cultivars have been selected in south Florida or introduced from other countries (Table 3). However, problems such as poor natural fruit set, fruit splitting, and uneven ripening have precluded their use commercially. Only the 'Gefner', introduced from Israel has proven commercially viable. However, local nursery people (Hahdeem 1990) and researchers at the USDA Subtropical Research Station, Miami, continue to develop and evaluate new germplasm in search of improved cultivars.

Plant spacing, fertilization, and irrigation. Moderate plant spacings (6 to 7 x 6 to 9 m) and plant densities (158 to 277 trees per ha) are suggested for atemoya groves. An industry survey found 42% of the current south Florida hectarage at low plant densities (143 to 215 trees per ha) and wide spacings (6.1 to 8.2 x 7.6 to 8.5 m), 34% at moderate plant densities (268 to 431 trees per ha) and spacings (3.8 to 6.1 x 6.1 to 7.0 m), and 24% at high plant densities (528 trees per ha) and close spacings (3.1 x 6.1 m) (Crane 1989). Most low density plantings are interplanted with another fruit crop such as sugar apple or carambola. Optimum plant spacings and densities have not yet been determined.

Little research has been conducted to determine the optimum fertilizer recommendations for atemoya. Current recommendations for young trees include bimonthly applications of 6-2.6-5.0 (NPK) or similar material at 100 g per tree (Campbell and Phillips 1980). As trees mature an 8-1.3-7.5 (NPK) or similar material should be applied 3 to 4 times per year at the rate of 450 g per tree per 2.5 cm of trunk diameter per application. To prevent micronutrient deficiencies, foliar application of magnesium, manganese, and zinc and soil drenches of chelated iron are typically made 2 to 4 times per year.

Irrigation is recommended during dry periods and has been observed to be important during bloom, fruit set, and fruit development (Campbell and Phillips 1980). Excessive irrigation or rainfall during fruit maturation may increase fruit splitting.

Pruning and tree size control. To date, little work has been done on the training and pruning of atemoya trees. Early recommendations (Campbell and Phillips 1980) suggested training young trees to an open center form to increase scaffold strength. Periodically thereafter, shoots should be headed back to keep trees manageable and easy to harvest.

Pollination. Atemoya flowers are protogynous with the flowers first functionally female; flowers begin to open in the late afternoon and by the following morning are fully open and receptive (Nagel et al. 1989). The flowers begin functioning as males by the late afternoon and early evening following the female stage. Usually, by this time however, the stigmas are dry and unreceptive, precluding self-pollination.

Atemoyas are successfully pollinated by a complex of beetles in the family Nitidulidae (commonly called sap beetles) (Nagel et al. 1989). These sap beetles are most abundant from 8:00 am to 4:00 pm and remain at the base of the flower for many hours. Hand-pollination is also practiced by some growers to insure adequate fruit set, increase early fruit set, and enhance fruit uniformity (Cockshutt 1990). Attempts to induce parthenocarpic fruit with gibberellic acid have not been successful (Campbell 1979).

Disease and insect pests. Atemoya fruit are attacked by the annona seed borer [Bephratelloides cubensis (Ashmead)], mealy bugs (Pseudococcus sp.), and Philephedra scale [Philephedra truberculosa (Nakahara & Gill)] (Pena 1986). Leaves and stems are attacked by Cyanophyllum scale [Abgrallafpif cyanophylli (Signoret)], Philephedra scale (Pena 1986), and ambrosia beetles (stems only) (Xylosandrus sp.) (Campbell and Phillips 1980).

Several diseases affect the fruit including anthracnose (Colletotrichum gloeosporioides Penz.) and Botryodiplodia theobromae Pat. (McMillan 1986). A rust fungus (Phokospora cherimoliae Cumm.) attacks leaves causing early defoliation (McMillan 1986). Recently, Pythium splendens Bruan has been shown to be the cause of a tree decline in commercial groves (Ploetz 1991). This decline is more prevalent in poorly drained or excessively wet groves.

Harvest, handling, and utilization. The atemoya season is generally from August to January with the peak during August through October. About 100 to 120 days are required from flowering to horticultural maturity and this depends upon the weather and cultural conditions. Mature trees may produce from 23 to 34 kg per tree, possibly more with good management.

Atemoya fruit are carefully clipped from the branches, leaving a small portion of the peduncle. Fruit are harvested when they have turned from green to greenish-yellow and the area between protuberances has filled out. Fruit have limited storage life (5 to 10 days) but can be held for several days at 13deg.C to slow ripening. The atemoya is primarily consumed as a fresh fruit but the pulp is used in desserts, salads, ice creams, and milk shakes.

MISCELLANEOUS COMMERCIAL TROPICAL FRUITS

In 1991, there were approximately 9,308 ha of commercial tropical fruit crops in south Florida (Table 5). Dade County had about 96% (8,903 ha), Lee County had about 353 ha, Collier and Broward Counties had 20 ha each, and Palm Beach County about 12 ha. A recent study (Mosely 1990) found gross sales of tropical fruits from Dade County, Florida, to be about $74 million annually (Table 6).

Avocados, limes, and mangos make up about 83% of the hectarage (Table 5). Smaller but significant commercial hectarage of atemoya, banana, carambola, mamey sapote, longan, lychee, papaya, passion fruit, and sugar apple also exist. There is also minor but increasing commercial hectarage of Barbados cherry, guava, kumquat, and sapodilla. A number of entrepreneurs have establish small plantings of canistel, black sapote, jaboticaba, jackfruit, pummelo, wampee, wax jambu, and white sapote.

Although many tropical fruit crops were introduced into Florida during the past 70 to 490 years (Table 7) (Knight 1987; Krome and Goldweber 1987; Wolfe 1937), only limes, grapefruit, avocados, mangos, and papayas have been successfully grown commercially (Krome and Goldweber 1987; Wolfe 1937). For the past 20 to 30 years, Barbados cherry, sapodilla, guava, banana, mamey sapote, and lychee have been grown on a limited commercial scale (Campbell 1970; Campbell 1971), and only during the last 5 to 10 years has commercial hectarage of carambola, atemoya, sugar apple, longan, kumquat, and passion fruit been established (Campbell 1983; Campbell 1986).

The potential for continued or expanded commercial development of various tropical fruit crops in south Florida varies by plant species (Table 5). For example, the outlook for increased avocado and mango hectarage is poor due to foreign competition from Central and South America; the outlook for increased lychee, pummelo, jackfruit, and sugar apple appears promising because of increasing demand by Asian and Hispanic Americans; the outlook for increased longan and canistel hectarage is limited by lack of improved cultivars or selections.

In South Florida, horticultural practices for crops such as avocados, limes, and mangos has been well researched and are well known (see references cited by Lamberts and Crane 1990). However, horticultural information on crops such as atemoya, Barbados cherry, passion fruit, and carambola is limited. For some crops, such as canistel, jaboticaba, wax jambu, and wampee information is almost nonexistent.

References to available literature concerning horticultural practices for the tropical fruit crops listed in Table 5, were compiled and discussed previously (Lamberts and Crane 1990). The following section will highlight some of the issues and problems facing new fruit crop development.

TROPICAL FRUIT INDUSTRY DEVELOPMENT

Limitations

There are numerous factors which impede the commercial development of new tropical fruit crops in South Florida. These include unfamiliarity with the crop by the general public, lack of funds for marketing and promotion by producers, limited production volume and season of availability, financial risk for the entrepreneur, marginally acceptable cultivars or selections from the producers standpoint, lack of pesticides and the recalcitrance of regulators to assist in registering pesticides for "minor" crops, and reluctance by county tax assessors to grant agricultural exemptions for land with new crops.

Unfamiliarity by the general population is one of the most limiting factors encountered when marketing any new tropical fruit crop. People unfamiliar with the crop usually do not know how to tell when the fruit is mature enough to eat, how to prepare it, and perhaps not even what part is edible. In addition, if the price per fruit is too high they may not want to risk buying something they may not like. Basically, exposure to the fruit and education of people in the wholesale and retail trade as well as the consumer must occur to create consumer demand for these new crops.

Funding for market development and promotion is a limiting factor for increasing the demand for tropical fruit crops. Generally, new tropical fruit crops are grown by entrepreneurs who have spotted a potential niche, such as an ethnic or novelty market. Local marketing and promotion of the crop is by word-of-mouth. This was the case with carambola and was probably the case for most of Florida's tropical fruit crops at one time or another. This seems to be adequate only initially, prior to increased competition among producers. Marketing and promotion on a larger scale is then necessary, but the funds are usually not available.

The volume and availability of fruit may also impede or limit commercial development. Production volume of new crops is almost always limited. This is because expansion of production may pose large financial risk by the entrepreneur and the area of production is limited. Early entrepreneurs may for various reasons wish for the volume of production to remain limited so prices remain high and/or they cannot afford to expand. In addition, a limited season of availability may in some cases limit demand for the tropical fruit crop because it must essentially be reintroduced each season.

The lack of suitable cultivars has had a pronounced negative effect on the commercial development of some tropical fruit crops such as longan, white sapote, and canistel. Sometimes, current cultivars may be adequate to meet local demand for quality and storage life but not withstand handling and storage requirements for longer distance distribution. Cultivars may also be unsuitable because of low yields (e.g., 'Brewster' lychee), unreliable bearing (e.g., 'Kohala' longan), short storage and shelf life (e.g., sugar apple, atemoya), poor taste, and insect and disease susceptibility.

Another impediment to the commercial development of tropical fruit crops in south Florida is the lack of registered pesticides for even basic cultural practices like weed control. The lack of chemicals increase the financial risk to growers who may loose their crop to insect and/or diseases and must use more costly and less efficient pest control methods. The lack of understanding and unwillingness on the part of the pesticide regulatory community to facilitate new crop development by streamlining the pesticide registration process slows new crop development at best and prevents it at worst. Programs such as the Interregional Project-4, designed to assist minor crop producers register pesticides, is of great assistance. However, the time frame from requesting the use of a particular pesticide to actual registration may take 2 to 5 years.

Finally, due to the unfamiliarity of local tax assessors with new crops, some entrepreneurs are denied agricultural exemptions for their groves. This increases the financial risk of the enterprise and may forestal or prevent the entry of potential producers.

Facilitation

There are several factors which may facilitate the commercial development of new tropical fruit crops in Florida, including large ethnic populations familiar with tropical fruit crops, potential for some tropical fruit crops to appeal to the general population, entrepreneurial producers and packinghouses, marketing and promotion, development and selection of improved cultivars, applied and basic research at federal and state institutions, and federal-state programs to facilitate pesticide registration, and tax breaks.

The development of local demand and markets for many of the tropical fruit crops grown in south Florida stems from Florida's large Hispanic (about 49%) (Israel and Stephenson 1990; Anon. 1991) and substantial Caribbean and Asian populations. Many people from Hispanic, Asian, and Caribbean countries are familiar with the tropical fruit crops which can be grown in south Florida and will pay good prices for the locally available fresh fruit.

The capacity for a new crop to be accepted by the general population is a primary factor in its potential demand and expanded commercial production. Tropical fruit crops currently seen to have appeal to the general public include carambola, lychee, guava, and passion fruit. Others such as jackfruit, pummelo, wax jambu, and white sapote have a good chance for increased production and commercialization to meet increasing ethnic demand.

Critical to the introduction and development of new tropical fruit crops are those individuals and companies willing to facilitate commercial development of tropical fruit crops by their efforts at producing and promoting them. These entrepreneurs base their efforts on early experiences with the crop on a small scale, investigation of potential markets, and a vision that the crop can succeed commercially. Local marketing and promotion of the crop by word-of-mouth or local advertising can help establish a consumer base from which to build. This is true of atemoyas, sugar apples, lychees, sapodilla, and guava, to name a few. Later, as the industry develops, professional literature and advertising by individuals and packinghouses becomes necessary to continue and expand consumer demand.

Institutions such as the USDA Subtropical Research Station and Germplasm Repository, the University of Florida's Tropical Research and Education Center, and Fairchild Tropical Garden Tropical Fruit Program assist in the development and commercialization of new tropical fruit crops by introducing, evaluating, and disseminating new plant material. Some horticultural research is being conducted on underdeveloped tropical fruit crops by researchers at these institutions during the early stages of commercialization. Of great importance also, are individuals in the nursery business involved in their own breeding and/or selection of new cultivars and the propagation and dissemination of this new material.

Registration of pesticides for use on "minor" crops is greatly facilitated by the Interregional Research Project-4 which is a joint effort by the USDA, State Agricultural Experiment Stations, Environmental Protection Agency, Food and Drug Agency, pesticide manufacturers, and growers (Anon. 1988). This program has enabled the generation of scientific data and information required by EPA and the States for registering a number of pesticides for use in tropical fruit production in south Florida.

Finally, agricultural tax exemptions, which lower the tax rates on property used for commercial agriculture can help to lower the financial risk many entrepreneurs have when beginning to produce a new crop on a commercial scale.

REFERENCES


Table 1. Estimated hectares of commercial carambola in Florida from 1971 to 1991.

Year Hectares Reference
1971 4 Campbell 1971
1983 12 Campbell 1983
1984 16 Knight et al. 1984
1985 24 Campbell et al. 1985
1986 61 Campbell 1986
1987 81 Campbell 1988
1988 137 Crane 1991
1989 176 Crane 1989
1990 192 Crane 1991
1991 243 Crane 1991


Table 2. Carambola cultivars introduced or developed and selected in South Floridaz.

Cultivar Origin of
introduction
Flavor Selected in
Florida
Commercial
potential
Comments
Arkin Thailand Sweet yes Excellent Major cultivar at present
B-2 Malaysia Sweet no Unknown Under evaluation
B-10 Malaysia Sweet no Unknown Under evaluation
B-16 Malaysia Sweet no Unknown Under evaluation
B-17 Malaysia Sweet no Unknown Under evaluation
Dah Pon Florida Sweet yes Poor Poor color, insipid
Demak Indonesia Sweet no Poor Bitter after-taste
Fwang Tung Thailand Sweet no Fair Poor color, thin ribs
Golden Star Hawaii Tart yes Poor Sweet when fully mature
Hew-1 Thailand Sweet no Poor Whitish spots on fruit
Kary Hawaii Sweet no Unknown Under evaluation
Maha Malaysia Sweet no Poor Poor color, thin ribs insipid
Mih Tao Taiwan Sweet no Poor Insipid
Newcomb Florida Tart yes Poor Too tart
Sri Kembangan Malaysia Sweet no Unknown Under evaluation
Star King Florida Tart yes Poor Too tart
Tean Ma Taiwan Sweet no Poor Insipid
Thayer Florida Tart yes Fair Too tart, poor flavor
zOnly named cultivars have been included. Numbered selections from open and hand pollinations have been evaluated but not listed here.


Table 3. Atemoya cultivars introduced or developed and selected in South Floridaz.

Cultivar Origin of
introductiony
Selected in
Florida
Commercial
potential
Commentsx
African Pridew South Africa no Poor Requires hand pollination, uneven fruit ripening
Bernitski Israel no Poor Poor fruit set, may require hand pollination
Bradley Florida yes Poor Requires hand pollination, fruit splits
Caves Florida yes Poor
Cherimata Egypt no Poor
Chirimorinon A Venezuela no Poor
Chirimorinon B Venezuela no Poor
Chirimorinon C Venezuela no Poor
Finny Egypt no Poor
Gefner Israel no Excellent Major cultivar in south Florida
Island Beauty Australia no
Island Gem Australia no Poor Small fruit, poor fruit set
Lindstrom Australia no Poor
Malali#1 Israel no Poor Poor fruit set
Malamud Israel no Poor
Page Florida yes Poor Fruit splitting
Pinks's Mammoth Australia no Poor Poor fruit set
Priestly Australia no Poor Requires hand pollination
Stermer Hawaii no Poor
zOnly named cultivars are included in the table.
yFlorida cultivars were selected from seedling populations.
xBlank space indicates insufficient data to comment.
wSynonymous with 'Kaller' which originated in Israel.


Table 4. Estimated hectares of commercial atemoya in Florida from 1985 to 1991.

Year Hectares Reference
1985 8 Anonymous 1986
1986 12 Campbell 1986
1988 18 Anonymous 1989
1989 19 Crane 1989
1990 28 J.H. Crane unpublished
1991 49 J.H. Crane unpublished


Table 5. Current estimated hectarage of tropical fruit crops in south Florida.

Common name Scientific name Estimated area of
production (ha)
Potential for
commercial expansion
Atemoya Annona cherimola L. x A. squamosa L. 49 Excellent
Avocado Persea americana Mill. 3,642 Poor
Banana Musa sp. hybrids 162 Good
Barbados cherry Malpighia glabra L. 11 Excellent
Black sapote Diospyros ebenaster Retz. <1 Fair
Canistel Pouteria campechiana Baehni <1 Fair
Carambola Averrhoa carambola L. 243 Good
Guava Psidium guajava L. 31 Excellent
Jaboticaba Myrciaria cauliflora Berg. <1 Fair
Jackfruit Artocarpus heterophyllus Lam. <1 Good
Kumquat Fortunella sp. 10 Good
Tahiti lime Citrus x 'Tahiti' 2,865 Excellent
Longan Euphoria longana Steud. 30 Fair
Lychee Litichi chinensis Sonn. 81 Excellent
Mamey sapote Calocarpum sapota Merr. 108 Fair
Mango Mangifera indica L. 1,172 Fair
Papaya Carica papaya L. 142 Good
Passion fruit Passiflora edulis Sims 41 Excellent
Plantain Musa sp. 81 Good
Pummelo Citrus grandis (L.) Osbeck 8 Good
Sapodilla Manilkara zapota Van Royen 8 Fair
Sugar apple Annona squamosa L. 41 Good
Wampee Clausena lansium (Lour.) Skeels <1 Fair
Wax jambu Syzygium samarangense Merr. et Perry <1 Good
White sapote Casimiroa edulis Llav. et Lex. <1 Excellent


Table 6. Current estimated gross crop value of tropical fruit crops produced in Dade County, Floridaz.

Commodity Total crop
value
(millions $)
Limes 28.4
Avocados 17.8
Mangos 14.9
Mamey sapote 2.5
Banana/plantain 1.2
Papayas 0.9
Othersy 8.3
Total 74.0
zData modified from Mosely (1990).
yIncludes carambola, passion fruit, lychee, atemoya, sugar apple, guava, kumquat, longan, and Barbados cherries.


Table 7. Year selected tropical fruit crops were introduced into Florida.

Tropical fruit Year
introduced
Reference
Atemoyaz 1908 Fairchild 1990; Morton 1987
Avocado 1833 Morton 1987
Bananay 1887 Knight 1987; Wolfe 1937
Barbados cherryy 1887 Knight 1987; Wolfe 1937
Black sapote 1919 Morton 1987
Canistely 1887 Knight 1987
Carambolay 1887 Knight 1987; Wolfe 1937
Guavax 1500s(1912) Ledin 1957; Morton 1987; Wolfe 1937
Jaboticaba 1913 Morton 1987
Jackfruit 1887 Morton 1987
Kumquat 1885 Ziegler and Wolfe 1981
Tahiti lime 1883 Morton 1987: Ziegler and Wolfe 1981
Longan 1903 Morton 1987
Lycheey 1883 Morton 1987: Wolfe 1937
Mamey sapotey 1887 Morton 1987; Wolfe 1937
Mangow 1833/1862 Crane and Campbell 1991; Morton 1987
Papaya 1500s Ledin 1957
Passion fruity 1887 Knight 1987; Wolfe 1937
Plantain 1500s Ledin 1957
Pummeloy 1887 Knight 1987
Sapodillay 1889 Knight 1987
Sugar appley 1887 Knight 1987; Wolfe 1937
Wampee 1908 Morton 1987
Wax jambu 1953 Whitman and Wirkus 1957
White sapotey 1887 Wolfe 1937
zHybrid of sugar apple and cherimoya developed in Florida.
yIntroduced sometime before 1887.
xFirst formal commercial planting established in 1912 (Morton 1987).
wIntroduced in 1833 but not successfully established until 1862 or 1863 (Morton 1987).


Fig. 1. 'Arkin' carambola.


Fig. 2. 'Gefner' (left) and 'African Pride' (right) atemoya.


Last update September 15, 1997